Methods and systems for subscriber identity management in a mobile device

ABSTRACT

Methods and systems for managing a pool of subscriber identities, and wirelessly provisioning mobile devices to use one or more of the subscriber identities when a subscriber is roaming on a different network. When a subscriber&#39;s mobile device connects to a visited network, a subscriber identity server can be notified. The subscriber identity server may have access to a plurality of available subscriber identities (e.g., registered to various service providers), and may select a suitable subscriber identity matching the subscriber&#39;s visited network. The subscriber identity can be communicated to the subscriber&#39;s mobile device, which can be reprogrammed to assume the new subscriber identity.

FIELD

The various embodiments described herein relate generally to subscriberidentity management in mobile devices and, in particular, to subscriberidentity management based on device location.

INTRODUCTION

To obtain wireless communication service, subscribers typically registeran account with a wireless network service provider. A subscriberaccount is typically associated with a unique subscriber identity and,if the service is a telephone service, a telephone number. The uniquesubscriber identity and telephone number are typically recorded in adatabase by the service provider. In the Global System for MobileCommunications (GSM) protocol, the unique subscriber identity is knownas an International Mobile Subscriber Identity (IMSI).

The IMSI is typically a 15-digit number, although it can have adifferent length in some implementations. The first 3 digits of the IMSIspecify the Mobile Country Code (MCC) associated with the subscriberidentity. The next 2 or 3 digits specify the Mobile Network Code (MNC)of the subscriber's service provider. The remaining digits comprise theMobile Subscription Identification Number (MSIN) associated with thesubscriber. The ITU E.212 numbering standard is commonly used for theIMSI. Each IMSI is generally unique to each service provider, and isthereby globally unique by virtue of incorporating the MCC and MNC.

The combination of the MCC and MNC is also referred to as the HomeNetwork Identity (HNI), which identifies the subscriber's home network.The network may also be referred to as a Public Land Mobile Network(PLMN).

Typically, the IMSI of each registered subscriber is permanently storedin a Home Location Register (HLR) operated by the service provider. Eachservice provider generally operates at least one HLR to service itsnetwork. A subscriber's “home network” is generally the network servedby the same provider's HLR that permanently stores the subscriber'sIMSI.

For regulatory and other reasons, wireless network service providerstypically operate wireless networks within a limited geographic area.However, subscribers often desire to maintain wireless network servicewhen travelling outside the geographic area serviced by their homenetwork. For this reason, a subscriber's wireless network serviceprovider will generally have reciprocal agreements with other serviceproviders to provide access while the subscriber is outside his or herhome network.

The ability of a subscriber to automatically make use of networkservices outside the subscriber's home network is commonly referred toas roaming. Roaming allows a subscriber and, more particularly, thesubscriber's mobile device, to access a “visited” network (i.e., anetwork accessed through the use of roaming), that is, a wirelessnetwork other than the subscriber's home network. In GSM, the GSMAssociation Permanent Reference Document AA.39 defines the servicessupported for a user while roaming: the ability to make and receivevoice calls, send and receive data, and access other services, includinghome data services, when travelling outside the geographical coveragearea of the home network.

DRAWINGS

For a better understanding of the various embodiments described herein,and to show more clearly how these various embodiments may be carriedinto effect, reference will be made, by way of example, to theaccompanying drawings which show at least one example embodiment, and inwhich:

FIG. 1 is a block diagram of a mobile device in one example embodiment;

FIG. 2 is a block diagram of an example embodiment of a communicationsubsystem component of the mobile device of FIG. 1;

FIG. 3 is a block diagram of a node of a wireless network in one exampleembodiment;

FIGS. 4A to 4C are system diagrams illustrating example connectivityscenarios for a mobile device;

FIG. 5 is a flowchart diagram for an example method of managingsubscriber identity at a mobile device;

FIG. 6 is a continuation of the flowchart diagram of FIG. 5; and

FIG. 7 is a flowchart diagram for an example method of managingsubscriber identity at a subscriber identity server.

DESCRIPTION OF VARIOUS EMBODIMENTS

It will be appreciated that for simplicity and clarity of illustration,where considered appropriate, reference numerals may be repeated amongthe figures to indicate corresponding or analogous elements. Inaddition, numerous specific details are set forth in order to provide athorough understanding of the embodiments described herein. However, itwill be understood by those of ordinary skill in the art that theembodiments described herein may be practiced without these specificdetails. In other instances, well-known methods, procedures andcomponents have not been described in detail so as not to obscure thedescription of various embodiments herein. Also, the description is notto be considered as limiting the scope of the embodiments describedherein. It should also be noted that the term coupled indicates that twoelements can be directly coupled to one another or coupled to oneanother through one or more intermediate elements.

In a broad aspect, there is provided a method for managing subscriberidentities on a mobile device, wherein the mobile device has a primarysubscriber identity associated therewith, and wherein a first home zoneis associated with the primary subscriber identity, the methodcomprising: wirelessly receiving a temporary subscriber identity from asubscriber identity server, wherein the temporary subscriber identityhas a second home zone associated therewith, and wherein the second homezone corresponds to a current location of the mobile device; storing thetemporary subscriber identity in a memory of the mobile device; andinitializing the mobile device to use the temporary subscriber identity.

In another broad aspect, the storing comprises replacing the primarysubscriber identity in the memory with the temporary subscriberidentity.

In another broad aspect, the method further comprises, prior toreceiving the temporary subscriber identity, determining the currentlocation of the mobile device; detecting that the current location is ina visited zone other than the first home zone; and in response to thedetecting, transmitting a temporary identity request to the subscriberidentity server, the temporary identity request comprising an indicationof the current location.

In some cases, the first home zone is a home network associated with theprimary subscriber identity. In some cases, the second home zone is ahome network associated with the temporary subscriber identity. In somecases, the visited zone is a visited network for the primary subscriberidentity. In some cases, the first home zone is a local location areaassociated with the primary subscriber identity. In some cases, thesecond home zone is a local location area associated with the temporarysubscriber identity. In some cases, the visited zone is a non-locallocation area for the primary subscriber identity.

In another broad aspect, the current location is determined based on oneor more properties of the visited zone. In some cases, the one or moreproperties comprise a Location Area Identity of the visited zone. Insome cases, the current location is determined using a wireless locationservice.

In another broad aspect, the method further comprises, prior toinitializing the mobile device to use the temporary subscriber identity,transmitting a request to a host system to forward communicationsaddressed to the primary subscriber identity to the temporary subscriberidentity.

In another broad aspect, the method further comprises: determining thatthe current location of the mobile device has changed from a previouszone to a new zone; detecting that the new zone is the first home zone;transmitting a release request to the subscriber identity server torelease the temporary subscriber identity; and re-initializing themobile device to use the primary subscriber identity. In some cases, there-initializing comprises replacing the temporary subscriber identity inthe memory with the primary subscriber identity.

In some cases, the memory is a programmable subscriber identity moduleprovided on the mobile device. In some cases, the programmablesubscriber identity module is configured to store a plurality ofidentities.

In another broad aspect, there is provided a method for managingidentity of a mobile device at a subscriber identity server, wherein themobile device has a primary subscriber identity associated therewith,and wherein a first home zone is associated with the primary subscriberidentity, the method comprising: determining that the mobile device isconnected to a wireless network in a visited zone other than the firsthome zone; selecting a temporary subscriber identity from a plurality ofavailable identities, wherein the selected temporary subscriber identityhas a second home zone associated therewith, and wherein the second homezone corresponds to a current location of the mobile device; andtransmitting the selected temporary subscriber identity to the mobiledevice.

In another broad aspect, the determining comprises receiving a temporaryidentity request from the mobile device, the temporary identity requestcomprising an indication of the current location of the mobile device.

In another broad aspect, the determining comprises receiving anotification that the mobile device has connected to the wirelessnetwork in the visited zone.

In another broad aspect, the method further comprises transmitting arequest to a host system to forward communications addressed to theprimary subscriber identity to the temporary subscriber identity.

In another broad aspect, the method further comprises updating adatabase to indicate that the temporary subscriber identity has beenassigned to the mobile device.

In another broad aspect, the method further comprises: receiving afurther notification that the mobile device has changed location; andupdating the database to indicate that the temporary subscriber identityis no longer assigned to the mobile device.

In some cases, the first home zone is a home network associated with theprimary subscriber identity. In some cases, the second home zone is ahome network associated with the temporary subscriber identity. In somecases, the visited zone is a visited network for the primary subscriberidentity. In some cases, the first home zone is a local location areaassociated with the primary subscriber identity. In some cases, thesecond home zone is a local location area associated with the temporarysubscriber identity. In some cases, the visited zone is a non-locallocation area for the primary subscriber identity.

In another broad aspect, there is provided a mobile device, wherein aprimary subscriber identity is associated the mobile device, and whereina first home zone is associated with the primary subscriber identity,the mobile device comprising: a memory; a communication subsystem, and aprocessor configured to carry out the methods described herein.

In another broad aspect, there is provided an apparatus for managingidentity of a mobile device, wherein the mobile device has a primarysubscriber identity associated therewith, and wherein a first home zoneis associated with the primary subscriber identity, the apparatuscomprising: a database and a processor configured to carry out themethods described herein.

To aid the reader in understanding the structure of an exampleimplementation of a mobile device, reference will be made to FIGS. 1 to3. However, it should be understood that the embodiments describedherein are not limited to a mobile device but can be extended to anyelectronic device that includes an image sensor and at least onenavigational sensor. Examples of such electronic devices may include anyportable electronic device such as cellular phones, cellularsmart-phones, wireless organizers, personal digital assistants,computers, laptops, handheld wireless communication devices, wirelessenabled notebook computers, tablet computers or e-readers, electronicsecurity devices, wireless Internet appliances and the like. Theelectronic devices listed herein which are mobile are generally portableand thus are battery-powered and may have limited processing power.While some of these devices include wireless communication capability,others are standalone devices that do not communicate with otherdevices.

Referring to FIG. 1, shown therein is a block diagram of one example ofa mobile device 100. The mobile device 100 comprises a number ofcomponents, the controlling component being a microprocessor 102, whichcontrols the overall operation of the mobile device 100. Communicationfunctions, including data and voice communications, are performedthrough a communication subsystem 104. The communication subsystem 104receives messages from and sends messages to a wireless network 200. Inthis example, the communication subsystem 104 is configured inaccordance with the Global System for Mobile Communication (GSM) andGeneral Packet Radio Services (GPRS) standards. In other embodiments,the communication subsystem 104 can be configured in accordance withother communication standards as described below. New standards arestill being defined, and it will be understood by persons skilled in theart that the various embodiments described herein should be able to beadapted to work with any other suitable standards that are developed inthe future. The wireless link connecting the communication subsystem 104with the wireless network 200 represents one or more different RadioFrequency (RF) channels, operating according to defined protocolsspecified for GSM/GPRS communications. With newer network protocols,these channels are capable of supporting both circuit-switched voicecommunications and packet-switched data communications.

Although the wireless network 200 associated with the mobile device 100is a GSM/GPRS wireless network in this example, the mobile device 100can be adapted to use other wireless networks in variant embodiments.For example, the different types of wireless networks that can beemployed include, but are not limited to, data-centric wirelessnetworks, voice-centric wireless networks, and dual-mode networks thatcan support both voice and data communications over the same physicalbase stations. Examples of networks also include, but are not limitedto, Code Division Multiple Access (CDMA), CDMA2000 networks, GSM/GPRSnetworks, 3G networks like EDGE, W-CDMA and UMTS, 4G/LTE networks andfuture technologies such as 5G networks. Some other examples ofdata-centric networks include WiFi 802.11, Mobitex™ and DataTAC™ networkcommunication systems. Examples of voice-centric data networks includePersonal Communication Systems (PCS) networks like GSM and Time DivisionMultiple Access (TDMA) systems. Examples of communicationprotocols/standards that the mobile device 100 can be adapted to be usedwith include, but are not limited to, 3GPP and 3GPP2, High-Speed PacketAccess (HSPA) standards such as High-Speed Downlink Packet Access(HSDPA), 3GPP LTE, LTE, LTE Advanced, WiMax, and Flash-OFDM.

The microprocessor 102 may also interact with additional subsystems suchas, for example, a Random Access Memory (RAM) 106, a flash memory 108, adisplay 110, an auxiliary input/output (I/O) subsystem 112, a data port114, a keyboard 116, a speaker 118, a microphone 120, short-rangecommunications subsystem 122 and other device subsystems 124.

Some of the subsystems of the mobile device 100 performcommunication-related functions, whereas other subsystems can provide“resident” or on-device functions. By way of example, the display 110and the keyboard 116 can be used for both communication-relatedfunctions, such as entering a text message for transmission over thenetwork 200, and device-resident functions such as a calculator or tasklist. Operating system software used by the microprocessor 102 istypically stored in a persistent store such as the flash memory 108,which can alternatively be a non-volatile memory (e.g., ROM, NVRAM,etc.) or similar storage element (not shown). Those skilled in the artwill appreciate that the operating system, specific device applications,or parts thereof, can be temporarily loaded into a volatile store suchas the RAM 106.

The mobile device 100 can send and receive communication signals overthe wireless network 200 after network registration or activationprocedures have been completed. Network access may be associated with asubscriber or user of the mobile device 100. To identify a subscriber,the mobile device 100 may use a SIM/RUIM card 126 (i.e. SubscriberIdentity Module or a Removable User Identity Module) to be inserted intoa SIM/RUIM interface 128 in order to communicate with a network. The SIMcard or RUIM 126 is one type of a conventional “smart card” that can beused to identify a subscriber of the mobile device 100 and topersonalize the mobile device 100, among other things. Without the SIMcard 126, the mobile device 100 may not be fully operational forcommunication with the wireless network 200. By inserting the SIMcard/RUIM 126 into the SIM/RUIM interface 128, a subscriber can accessall subscribed services. Services may include, for example: web browsingand messaging such as e-mail, voice mail, SMS, and MMS. More advancedservices may include, for example: point of sale, field service andsales force automation. The SIM card/RUIM 126 typically includes aprocessor and memory for storing information. Once the SIM card/RUIM 126is inserted into the SIM/RUIM interface 128, it is coupled to themicroprocessor 102. In order to identify the subscriber, the SIMcard/RUIM 126 contains some user parameters such as the IMSI, whichcollectively comprise a subscriber identity that can be used to accesswireless network services to which the subscriber is subscribed.Examples of subscriber information that may form the subscriber identityinclude the IMSI, Mobile Subscriber Integrated Services Digital Network(MSISDN) Number, and authentication key associated with a subscriber. Inother embodiments, the subscriber identity may comprise otherinformation, such as the International Mobile Equipment Identity (IMEI)of a mobile device.

An advantage of using the SIM card/RUIM 126 is that a subscriber is notnecessarily bound to any single physical mobile device, as the SIM/RUIM126 itself stores the subscriber identity, and can be removed and usedin another mobile device. Likewise, a different SIM card/RUIM 126 can beused in place of the current SIM/RUIM 126 in a mobile device.

The SIM card/RUIM 126 can also store additional subscriber informationfor a mobile device as well, including datebook (or calendar)information and recent call information. Alternatively, useridentification information can also be programmed into a memory, such asthe flash memory 108.

In some cases, the SIM/RUIM 126 may be programmable. Accordingly,microprocessor 102 may be able to change the IMSI and other userparameters of the SIM/RUIM 126.

In some cases, the SIM/RUIM interface 128 may comprise two or moreinterfaces, to facilitate support of two or more SIM/RUIM 126. Forexample, the mobile device may accept two physical SIM cardssimultaneously, and provide a user interface for selecting between thetwo.

Alternatively, or in addition, the mobile device may comprise aprogrammable identity module 160 that duplicates some or all of thefunctionality of the SIM/RUIM 126 (e.g., IMSI, MSISDN and authenticationkey storage), in which case the IMSI and other user parameters may bestored in a memory, for example flash memory 108.

In some cases, SIM/RUIM 126 may store a plurality of mobile networkcodes (MNCs) or network identifiers, which can be defined by thesubscriber's service provider to indicate preferred networks that may beaccessed for the purposes of roaming. In this way, when the subscriberis outside the home network and has access to a plurality of possiblevisited networks, a preferred network can be selected first.

Each SIM/RUIM 126 may have an authentication key (Ki) assigned to it bya service provider when the SIM/RUIM is first “personalized”. Theauthentication key is a 128-bit value used to authenticate the SIM/RUIMon a mobile network. Each SIM/RUIM holds a unique Ki assigned to it bythe operator during the personalization process. The authentication keyis also stored in a database by the service provider and may beassociated with a subscriber or the subscriber's IMSI.

Generally, the SIM/RUIM 126 may be designed to prevent access to theauthentication key via the conventional smart card interface of theSIM/RUIM. In order to use the authentication key, data may be input tothe smart card and the smart card can be instructed to perform acryptographic signing function using the authentication key and thedata. The requirement for both the authentication key and the IMSI toauthenticate a subscriber on a wireless network can provide a measure ofsecurity, by ensuring that the SIM/RUIM is present to performauthentication functions.

However, in some cases, the service provider may reveal theauthentication key, allowing the SIM/RUIM data to be duplicated orcopied. In other cases, the authentication key can be extracted from theSIM/RUIM, for example by exploiting vulnerabilities in the cryptographicalgorithms used by the SIM/RUIM.

The SIM/RUIM may also store network state information, including acurrent or last-known Location Area Identity (LAI) number. In somecases, when a mobile device enters a new location, it may store the LAIof the new location (e.g., in the SIM/RUIM) and transmit the LAI to thenetwork to identify its current location.

The mobile device 100 is typically a battery-powered device and includesa battery interface 132 and may use one or more rechargeable batteriesin a battery unit 130. The battery interface 132 may be coupled to aregulator (not shown), which assists the battery unit 130 in providingpower V+ to the mobile device 100. Alternatively, the battery unit 130can be a smart battery as is known in the art. Smart batteries generallyinclude a battery processor, battery memory, switching and protectioncircuitry, measurement circuitry and a battery pack that includes one ormore batteries, which are generally rechargeable. In either case, theone or more batteries in the battery unit 130 can be made from lithium,nickel-cadmium, lithium-ion, or other suitable composite material.

The microprocessor 102, in addition to its operating system functions,enables execution of software applications 134 on the mobile device 100.The subset of software applications 134 that control basic deviceoperations, including data and voice communication applications, willnormally be installed on the mobile device 100 during its manufacture.When the microprocessor 102 is executing any of the softwareapplications 134, the microprocessor 102 can be considered to beconfigured to execute a number of acts according to the methodsspecified by the code of the software applications 134.

The software applications 134 may include a message application 136 thatcan be any suitable software program that allows a user of the mobiledevice 100 to send and receive electronic messages. Various alternativesexist for the message application 136 as is well known to those skilledin the art. Messages that have been sent or received by the user aretypically stored in the flash memory 108 of the mobile device 100 orsome other suitable storage element in the mobile device 100.Alternatively, some of the sent and received messages can be storedremotely from the device 100 such as in a data store of an associatedhost system that the mobile device 100 communicates with. For instance,in some cases, only recent messages can be stored within the device 100while the older messages can be stored in a remote location such as thedata store associated with a message server. This can occur when theinternal memory of the device 100 is full or when messages have reacheda certain “age”, i.e. messages older than 3 months can be stored at aremote location. As a further alternative, all messages can be stored ina remote location while only recent messages can be stored on the mobiledevice 100.

The mobile device 100 may include, for example, a camera module 138, adevice state module 140, an address book 142, a Personal InformationManager (PIM) 144, and other modules 146. The camera module 138 is usedto control the camera operation for the mobile device 100, whichincludes obtaining raw thumbnail image data associated with images takenby an image sensor of the mobile device 100, preprocessing the rawthumbnail image data, and displaying the processed thumbnail image dataon the display 110.

The device state module 140 provides persistence, i.e. the device statemodule 140 ensures that important device data is stored in persistentmemory, such as the flash memory 108, so that the data is not lost whenthe mobile device 100 is turned off or loses power. The address book 142provides information for a list of contacts for the user. For a givencontact in the address book 142, the information can include the name,phone number, work address and email address of the contact, among otherinformation. The other modules 146 can include a configuration module(not shown) as well as other modules that can be used in conjunctionwith the SIM/RUIM interface 128.

The PIM 144 has functionality for organizing and managing data items ofinterest to a subscriber, such as, but not limited to, e-mail, calendarevents, voice mails, appointments, and task items. A PIM application hasthe ability to send and receive data items via the wireless network 200.PIM data items can be seamlessly integrated, synchronized, and updatedvia the wireless network 200 with the mobile device subscriber'scorresponding data items stored and/or associated with a host computersystem. This functionality creates a mirrored host computer on themobile device 100 with respect to such items. This can be particularlyadvantageous when the host computer system is the mobile devicesubscriber's office computer system.

Additional applications can also be loaded onto the mobile device 100through at least one of the wireless network 200, the auxiliary I/Osubsystem 112, the data port 114, the short-range communicationssubsystem 122, or any other suitable device subsystem 124. Thisflexibility in application installation increases the functionality ofthe mobile device 100 and can provide enhanced on-device functions,communication-related functions, or both. For example, securecommunication applications can enable electronic commerce functions andother such financial transactions to be performed using the mobiledevice 100.

The data port 114 enables a subscriber to set preferences through anexternal device or software application and extends the capabilities ofthe mobile device 100 by providing for information or software downloadsto the mobile device 100 other than through a wireless communicationnetwork. The alternate download path can, for example, be used to loadan encryption key onto the mobile device 100 through a direct and thusreliable and trusted connection to provide secure device communication.

The data port 114 can be any suitable port that enables datacommunication between the mobile device 100 and another computingdevice. The data port 114 can be a serial or a parallel port. In someinstances, the data port 114 can be a USB port that includes data linesfor data transfer and a supply line that can provide a charging currentto charge the mobile device 100.

The short-range communications subsystem 122 provides for communicationbetween the mobile device 100 and different systems or devices, withoutthe use of the wireless network 200. For example, the subsystem 122 caninclude an infrared device and associated circuits and components forshort-range communication. Examples of short-range communication mayinclude, for example, standards developed by the Infrared DataAssociation (IrDA), Bluetooth, and the 802.11 family of standardsdeveloped by IEEE.

In use, a received signal such as a text message, an e-mail message, orweb page download will be processed by the communication subsystem 104and input to the microprocessor 102. The microprocessor 102 will thenprocess the received signal for output to the display 110 oralternatively to the auxiliary I/O subsystem 112. A subscriber can alsocompose data items, such as e-mail messages, for example, using thekeyboard 116 in conjunction with the display 110 and possibly theauxiliary I/O subsystem 112. The auxiliary subsystem 112 can includedevices such as a touch screen, mouse, track ball, infrared fingerprintdetector, or a roller wheel with dynamic button pressing capability. Thekeyboard 116 is preferably an alphanumeric keyboard and/ortelephone-type keypad. However, other types of keyboards can also beused. A composed item can be transmitted over the wireless network 200through the communication subsystem 104.

For voice communications, the overall operation of the mobile device 100is substantially similar, except that the received signals are output tothe speaker 118, and signals for transmission are generated by themicrophone 120. Alternative voice or audio I/O subsystems, such as avoice message recording subsystem, may also be implemented on the mobiledevice 100. Although voice or audio signal output is accomplishedprimarily through the speaker 118, the display 110 can also be used toprovide additional information such as the identity of a calling party,duration of a voice call, or other voice call related information.

The mobile device 100 may include a camera unit 148 that allows a userof the mobile device 100 to capture images and videos. The camera unit148 can include a camera controller, a current drive unit, a camera lenssub-unit, a camera flash sub-unit, a camera sensor sub-unit and an imagecapture input (not shown). The camera controller configures theoperation of the camera unit in conjunction with information andinstructions received from the microprocessor 102 and the camera module138.

Mobile device 100 may further comprise a navigational sensor unit 150,which may comprise one or more navigational sensors, such as a gyroscope154, accelerometer 152, and a magnetometer 156. Memory 108 may storecalibration parameters or sensor data associated with one or more of thenavigational sensors. In some other embodiments, navigational sensorunit 150 may comprise or have access to additional memory (not shown)internal to the navigational sensor unit 150.

Accelerometer 152 is a non-magnetometer sensor operable to obtain orotherwise acquire data such as data measuring the acceleration of aninertial reference frame relative to the accelerometer. Such data can bestored in a data store, such as memory 108. Gyroscope 154 is anon-magnetometer sensor operable to obtain or otherwise acquire datasuch as data measuring the orientation of mobile device 100 relative toone or more axes. Such data can be stored in a data store, such asmemory 108. Magnetometer 156 is operable to obtain or otherwise acquiredata such as data measuring the direction of a magnetic field and itsstrength. In some cases, magnetometer 156 may provide data representingproperties of a three-dimensional magnetic field. For example, the datamay comprise a magnetic field vector, comprising a scalar magnitude andangular values (e.g., bearing, azimuth, inclination). Such data can bestored in a data store, such as memory 108.

In some embodiments, a Global Positioning System (GPS) unit 158 may alsobe provided on mobile device 100. GPS unit 158 is operable to obtain orotherwise acquire position data such as, for example, longitude,latitude and elevation using a global navigation satellite system suchas the Global Positioning System, Galileo, GLONASS or the like. Suchdata can be stored in a data store, such as memory 108. Variousapplications may utilize the stored GPS unit data.

Navigation sensor unit 150 may provide a data communication interfaceenabling data communication with microprocessor 102 and various othersubsystems of mobile device 100.

Referring now to FIG. 2, a block diagram of the communication subsystemcomponent 104 of FIG. 1 is shown. Communication subsystem 104 comprisesa receiver 180, a transmitter 182, one or more embedded or internalantenna elements 184, 186, Local Oscillators (LOs) 188, and a processingmodule such as a Digital Signal Processor (DSP) 190.

The particular design of the communication subsystem 104 is dependentupon the network 200 in which the mobile device 100 is intended tooperate; thus, it should be understood that the design illustrated inFIG. 2 serves only as one example. Signals received by the antenna 184through the network 200 are input to the receiver 180, which may performsuch common receiver functions as signal amplification, frequency downconversion, filtering, channel selection, and analog-to-digital (A/D)conversion. A/D conversion of a received signal allows more complexcommunication techniques such as demodulation and decoding to beperformed in the DSP 190. In a similar manner, signals to be transmittedare processed, including modulation and encoding, by the DSP 190. TheseDSP-processed signals are input to the transmitter 182 fordigital-to-analog (D/A) conversion, frequency up conversion, filtering,amplification and transmission over the network 200 via the antenna 186.The DSP 190 not only processes communication signals, but also providesfor receiver and transmitter control. For example, the gains applied tocommunication signals in the receiver 180 and the transmitter 182 may beadaptively controlled through automatic gain control algorithmsimplemented in the DSP 190.

The wireless link between the mobile device 100 and a network 200 maycontain one or more different channels, typically different RF channels,and associated protocols used between the mobile device 100 and thenetwork 200. An RF channel is a limited resource that must be conserved,typically due to limits in overall bandwidth and limited battery powerof the mobile device 100.

When the mobile device 100 is fully operational, the transmitter 182 istypically keyed or turned on only when it is sending to the network 200and is otherwise turned off to conserve resources. Similarly, thereceiver 180 is periodically turned off to conserve power until it isneeded to receive signals or information (if at all) during designatedtime periods.

Referring now to FIG. 3, a block diagram of a node of a wireless networkis shown as 202. In this example embodiment, the network and itscomponents are described for operation with GPRS and GSM technologies.However, it should be understood that in other embodiments the networkcan be implemented in accordance with other communication protocols. Inpractice, the network 200 comprises one or more nodes 202. The mobiledevice 100 communicates with a node 202 within the wireless network 200.The node 202 may be configured in accordance with GPRS and GSMtechnologies. The node 202 may include a base station controller (BSC)204 with an associated tower station 206, a Packet Control Unit (PCU)208 added for GPRS support in GSM, a Mobile Switching Center (MSC) 210,an HLR 212, a VLR 214, a Serving GPRS Support Node (SGSN) 216, a GatewayGPRS Support Node (GGSN) 218, and a Dynamic Host Configuration Protocol(DHCP) 220. This list of components is not meant to be an exhaustivelist of the components of every node 202 within a GSM/GPRS network, butrather a list of components that may be commonly used in communicationsthrough the network 200.

In a GSM network, the MSC 210 is coupled to the BSC 204 and to alandline network, such as a Public Switched Telephone Network (PSTN) 222to satisfy circuit switched requirements. The connection through the PCU208, the SGSN 216 and the GGSN 218 to the public or private network(Internet) 224 (also referred to herein generally as a shared networkinfrastructure) represents the data path for GPRS capable mobiledevices. In a GSM network extended with GPRS capabilities, the BSC 204also contains a Packet Control Unit (PCU) 208 that connects to the SGSN216 to control segmentation, radio channel allocation and to satisfypacket switched requirements. To track mobile device location andavailability for both circuit switched and packet switched management,the HLR 212 is shared between the MSC 210 and the SGSN 216. Access tothe VLR 214 is controlled by the MSC 210.

The station 206 may be a fixed transceiver station in which case thestation 206 and the BSC 204 together form the fixed transceiverequipment. The fixed transceiver equipment provides wireless networkcoverage for a particular coverage area commonly referred to as a“cell”. The fixed transceiver equipment transmits communication signalsto and receives communication signals from mobile devices within itscell via the station 206. The fixed transceiver equipment normallyperforms such functions as modulation and possibly encoding and/orencryption of signals to be transmitted to the mobile device inaccordance with particular, usually predetermined, communicationprotocols and parameters, under control of its controller. The fixedtransceiver equipment similarly demodulates and possibly decodes anddecrypts, if necessary, any communication signals received from themobile device 100 within its cell. Communication protocols andparameters may vary between different nodes. For example, one node mayemploy a different modulation scheme and operate at differentfrequencies than other nodes.

For all subscriber identities registered with a specific network,permanent configuration data such as a user profile, IMSI, MSISDN, andthe like, may be stored in the HLR 212. The HLR 212 may also containlocation information for each mobile device using a registeredsubscriber identity and can be queried to determine the current locationof a mobile device. The MSC 210 is responsible for a group of locationareas and stores the data of the mobile devices currently in its area ofresponsibility in the VLR 214. Further the VLR 214 also containsinformation on mobile devices that are visiting other networks. Theinformation in the VLR 214 includes part of the permanent mobile devicedata transmitted from the HLR 212 to the VLR 214 for faster access. Bymoving additional information from a remote node of the HLR 212 to theVLR 214, the amount of traffic between these nodes can be reduced sothat voice and data services can be provided with faster response timeswhile at the same time using less computing resources.

The SGSN 216 and the GGSN 218 are elements added for GPRS support;namely packet switched data support, within GSM. The SGSN 216 and theMSC 210 have similar responsibilities within wireless network 200 bykeeping track of the location of each mobile device 100. The SGSN 216also performs security functions and access control for data traffic onthe network 200. The GGSN 218 provides internetworking connections withexternal packet switched networks and connects to one or more SGSN's 216via an Internet Protocol (IP) backbone network operated within thenetwork 200. During normal operations, a given mobile device 100typically performs a “GPRS Attach” to acquire an IP address and toaccess data services. This would not typically be present in circuitswitched voice channels as Integrated Services Digital Network (ISDN)addresses are used for routing incoming and outgoing calls. GPRS capablenetworks may use private, dynamically assigned IP addresses, and a DHCPserver 220 connected to the GGSN 218. There are many mechanisms fordynamic IP assignment, including using a combination of a RemoteAuthentication Dial-In User Service (RADIUS) server and a DHCP server.Once the GPRS Attach is complete, a logical connection is establishedfrom a mobile device 100, through the PCU 208 and the SGSN 216 to anAccess Point Node (APN) within the GGSN 218. The APN represents alogical end of an IP tunnel that can either access direct Internetcompatible services or private network connections. The APN alsorepresents a security mechanism for the network 200, insofar as eachmobile device 100 must be assigned to one or more APNs and the mobiledevices 100 cannot exchange data without first performing a GPRS Attachto an APN that it has been authorized to use. The APN may be consideredto be similar to an Internet domain name such as“myconnection.wireless.com”.

Once the GPRS Attach is complete, a tunnel is created and traffic isexchanged within standard IP packets using any protocol that can besupported in IP packets. This includes tunneling methods such as IP overIP as in the case with some IPSecurity (IPsec) connections used withVirtual Private Networks (VPN). These tunnels are also referred to asPacket Data Protocol (PDP) Contexts and there are a limited number ofthese available in the network 200. To maximize use of the PDP Contexts,the network 200 will run an idle timer for each PDP Context to determineif there is a lack of activity. When a mobile device 100 is not usingits PDP Context, the PDP Context can be deallocated and the IP addressreturned to the IP address pool managed by the DHCP server 220.

The host system 250 may be a corporate enterprise or other local areanetwork (LAN), but may also be a home office computer or some otherprivate system, for example, in variant embodiments. In some cases, thehost system 250 may represent a smaller part of a larger network of anorganization. Typically, mobile devices communicate wirelessly with thehost system 250 through one or more of the nodes 202 of the wirelessnetwork 200. The host system 250 may include one or more routers andcomputing devices that may operate from behind a firewall or proxyserver. The proxy server routes data to the correct destinationserver(s) within the host system 250. For instance, the host system 250may include a message server to send and receive messages to the mobiledevices and a message management server that controls when, if, and howmessages are sent to the mobile devices. The host system 250 can alsoinclude other servers that provide various functions for the host system250 as well as data stores or databases.

In some embodiments, host system 250 may comprise a subscriber identityserver 290. Subscriber identity server 290 may comprise a processor,volatile and non-volatile memory, input-output interfaces (including atleast one network interface) and various application modules.Application modules may include, for example, a notification modulewhich may be notified when a mobile device connects to a visitednetwork, a subscriber identity management module to manage availablesubscriber identities, and a communication management module to managecall and services forwarding (not shown). Subscriber identity server 290may also have access to a subscriber identity database 295, which isconfigured to store a plurality of available subscriber identities to beused as described herein.

In some cases, the features and functionality of subscriber identityserver 290 and subscriber identity database 295 may be integrated withother components of host system 250, such as the message server ormessage management server.

As noted above, the HLR is one type of database operated by wirelessnetwork service providers, which contains information regarding eachsubscriber identity authorized to use the wireless network. There may beseveral logical or physical HLRs for each wireless network. For example,several HLRs may be provided on computer servers physically distributedacross a wireless network, but may be synchronized together to act as asingle, logical HLR.

Subscriber information stored by the HLR includes the IMSI of eachsubscriber and may include at least one MSISDN number of the subscriber.The MSISDN is a number used to make and receive voice calls and textmessages. Other information stored by the HLR typically includes dataassociated with subscribed services, current location of the subscriber(e.g., Location Area Code, last known VLR, current support node, etc.),and call diversion settings (e.g., call forwarding information) for eachMSISDN.

To update the current location of the subscriber when the mobile deviceis operated in a new location area (either within the home network orotherwise), a Location Area update procedure may be followed. Thesubscriber information is first transmitted from the subscriber's HLR tothe VLR or support node of the subscriber's new Location Area.Subsequently, the subscriber's HLR may communicate with the new VLR toestablish how incoming communications are to be delivered to the mobiledevice. Finally, the subscriber's HLR may notify a previous VLR that thesubscriber is in a new location area, and that the subscriberinformation (which was previously retrieved and stored in a similarmanner) can be removed by the previous VLR.

Generally, the VLR is a database identifying subscriber information formobile devices in the location area served by a MSC. Typically, eachwireless base station in a network is served by only one VLR. To ensurethat communications can be accurately delivered at all times, wirelessnetworks will attempt to maintain subscriber information at only one VLRat a time (i.e., at the VLR serving the location area in which thesubscriber's mobile device is connected).

The VLR may store subscriber information received from an HLR, or fromthe mobile device itself. Subscriber information stored by the VLR mayinclude IMSI or Temporary Mobile Subscriber Identity (TMSI),authentication data, MSISDN, subscribed services, and the subscriber'shome HLR identifier.

Subscriber information may be removed from the VLR upon receiving anotification that the subscriber has left the location area served bythe VLR, or after a predetermined inactivity period.

As noted above, service providers typically store a permanent subscriberidentity record in an HLR. In order to provide services to a mobiledevice outside of its home network (i.e., to facilitate roamingfunctions), a temporary subscriber identity may also be stored by thevisited network, typically for as long as the mobile device is presentin the visited network. Accordingly, a home network and visited networkfor a particular subscriber can be defined, and a determination ofwhether the mobile device is in its home network or a visited networkcan be made based on the existence or type of subscriber identityrecorded in the HLR of a network.

When a subscriber's mobile device first connects to a visited network,it may attempt to use roaming functionality. If there is no entry forthe subscriber in the HLR of the visited network, the requiredsubscriber identity record can be requested by the visited network, forexample from the subscriber's home network. Thereafter, a temporarysubscriber identity can be stored in a Visitor Location Register (VLR)of the visited network.

The specific details of the roaming process may differ based on the typeof cellular network, however generally the roaming process begins with amobile device connecting to a visited network for the first time, eitherbecause the mobile device has been powered on, or has been “handed off”to the visited network by another network (in mobile communications, theterm “handover” or “handoff” refers to the process of transferring anongoing call or data session from one channel, cell, or network toanother). The mobile device detects that it is not connected to its homenetwork and may attempt to contact its home network.

The visited network may detect that the mobile device does not have aknown subscriber identity in its own HLR, and may contact the homenetwork of the mobile device's subscriber identity (i.e., thesubscriber's home network) to request subscriber identity data andservice information (including whether the mobile device should beallowed to make use of roaming functionality). Typically, the requestspecifies the IMSI of the mobile device.

If a response is received from the subscriber's home network thatauthorizes the mobile device to make use of roaming, the visited networkmay create a temporary subscriber record for the device. The homenetwork of the subscriber may also record that the mobile device isconnected to the visited network, so that any data addressed to themobile device can be routed correctly.

For example, if an incoming voice call is directed to a mobile deviceusing roaming functionality, the incoming call may first be directed bythe public switched telephone network to the home network of the mobiledevice, and then the home network may re-route the call to the mobiledevice on the visited network.

Generally, for a subscriber to be allowed to operate in a roaming modeon a visited network, a roaming agreement between the service providersof the home network and visited network is in place.

Roaming agreements typically specify billing procedures and costs.Generally, the cost for accessing network services in a visited networkare higher than when those same network services are accessed in asubscriber's home network. Thus, subscribers may prefer to avoid orminimize the use of network services when operating a mobile device on avisited network.

Types of Roaming

The preceding description describes a traditional form of roaming, whichmay be further categorized as either “international roaming” or“national roaming”.

International roaming and national roaming are largely similar. Bothprovide the ability for a subscriber to move from one wireless networkto another. In the case of international roaming, the wireless networkstraversed may be in different countries. In the case of nationalroaming, the wireless networks may be in the same country, but operatedby different wireless network service providers. In some cases, thewireless networks may be physically distinct, although this need not bethe case.

The term “roaming” may also be used informally to refer to the use ofnetwork services outside of a “local” area in a single wireless network.This “regional roaming” is generally found where network service, or thecost thereof, is differentiated regionally within a single wirelessnetwork. For example, service providers may define “local” and “roaming”calling areas for subscribers, where the “local” area for a particularsubscriber may be determined geographically based on the subscriber'shome address (or telephone number). In this case, the subscriber may beconsidered to be “roaming” when leaving the geographically defined“local” calling area. The local calling area may be thus definedlogically, or based on business rules, rather than any physical ortechnical requirements of the particular wireless network. Generally,the subdivisions of the network may be based on Location Areas withinthe network, with each Location Area having an LAI or Location Area Code(LAC) number.

The term “home zone” is defined herein as a “home network” in theinternational or national roaming scenario, and as a “local” LocationArea in the case of regional roaming.

Correspondingly, the term “visited zone” is defined herein as a “visitednetwork” (i.e., a network other than the home network associated withthe primary subscriber identity) in the international or nationalroaming scenario, and as a “non-local” Location Area (i.e., other thanthe subscriber's “local” area) in the case of regional roaming.

As used herein, the term “zone” refers to a network or some portion of anetwork, rather than a geographical area. It will be appreciated that,in some cases, a network zone nevertheless may be closely correlatedwith a geographical area served by the network. For example, a LocationArea within a network is generally closely correlated to thegeographical area containing the cellular base stations that make up theLocation Area.

Generally, the cost associated with network services used while in avisited zone will be higher than when within the home zone.

Many enterprises provide and support a plurality of mobile devices foruse by their employees. Some of these employees may wish to traveloutside of their home networks for business or personal reasons.However, due to the higher costs associated with the use of mobiledevices in a visited zone, the enterprise may incur higher costs whenthese employees use their mobile devices while travelling.

To reduce costs, some enterprises maintain a physical pool of “roaming”SIM cards registered to various wireless networks. When an employeeknows in advance that he will be visiting a specific region serviced bya particular service provider, then a suitable “roaming” SIM card (e.g.,one that is registered to the service provider that operates thewireless network in the region to be visited) can be borrowed from thepool. Accordingly, the employee can physically replace the original SIMcard in his mobile device with the roaming SIM card while away, toreduce the cost of using wireless network services.

However, managing such a pool of roaming SIM cards can be inconvenientand impose other costs. For example, employees may not know in advancewhich networks they will need to use while traveling. Shipment of SIMcards can be costly, and there may be other costs incurred due to lostSIM cards and the like.

Described herein are some example embodiments of systems and methods formanaging a pool of subscriber identities that can be dynamicallyassigned to a mobile device over a network.

In the example of international roaming, when a subscriber's mobiledevice connects to a visited network, a subscriber identity server(e.g., a message management server associated with the enterprise or thesubscriber's home network) can be notified. The subscriber identityserver may have access to a plurality of available subscriber identities(e.g., registered with service providers in various countries), and mayselect a suitable subscriber identity for which the subscriber's visitednetwork is a home network. For example, if the subscriber's home networkis “A-Mobile” in Germany and the subscriber's mobile device is connectedto the “Green” network in the United Kingdom, then a subscriber identitythat is registered to the “Green” network in the United Kingdom may beselected as the temporary subscriber identity.

The selected subscriber identity can be communicated to the subscriber'smobile device, which can store the new, temporary subscriber identity ina programmable module (e.g., programmable SIM, flash memory, etc.) atthe subscriber's mobile device. Subsequently, the new, temporarysubscriber identity can be used in place of the original, primarysubscriber identity on the mobile device, thus allowing the subscriberto avoid making use of roaming services.

Optionally, as part of the subscriber identity change, the subscriberidentity server can configure the subscriber's original HLR to forwardcalls to the temporary subscriber identity at the mobile device (or, insome cases, to the mobile device itself), to ensure that incoming callsand data communications directed to the primary subscriber identity canstill be received while using the temporary subscriber identity.

In cases where the original subscriber identity is deleted oroverwritten at the mobile device when a temporary subscriber identity isstored, the original subscriber identity can be restored when thesubscriber once again connects to the original home network (e.g., byreplacing the temporary subscriber identity with the original subscriberidentity).

Subscriber identities managed by the subscriber identity server can bepurchased and/or registered in advance or as-needed with various networkservice providers.

In some cases, subscriber information may be copied from existingphysical SIM cards using a reader device, to create subscriberidentities managed by the subscriber identity server.

A similar process may be used in the case of regional roaming (e.g.,within the same wireless network), whereby the temporary subscriberidentity may be selected based on the current location area of thesubscriber's mobile device. For example, if a subscriber's local callingarea is New York and the subscriber's mobile device is connected to thesame wireless network in Los Angeles, then a temporary subscriberidentity that has a local calling area of Los Angeles may be selected.

Connectivity Scenarios

Referring now to FIGS. 4A to 4C, there are shown system block diagramsillustrating example connectivity scenarios for a mobile device.

1—No Roaming

In connectivity scenario 400A, mobile device 100 is connected to homenetwork 410, which is the home network of the subscriber identitycurrently used by mobile device 100. In this scenario, the home networkis the home zone of the primary subscriber identity used by mobiledevice 100, and visited network 420 is the visited zone. Visited network420 is not presently accessible to, or within range of, mobile device100.

Accordingly, in connectivity scenario 400A, mobile device 100 does notmake use of roaming functionality.

2—International/National Roaming

As in connectivity scenario 400A, in connectivity scenario 400B, thehome network 410 is the home zone of the primary subscriber identityused by mobile device 100, and visited network 420 is the visited zone.

In connectivity scenario 400B, home network 410 is no longer accessibleto mobile device 100 (e.g., because the mobile device is physically outof range). However, visited network 420 is accessible to mobile device100, and mobile device 100 attempts to connect to visited network 420.

3—Regional Roaming

In contrast to connectivity scenarios 400A and 400B, in connectivityscenario 400C, mobile device 100 can stay connected only to home network410. Home network 410 has a plurality of location areas 412, 414 and416. However, location area 412 is defined as the “local” area of mobiledevice 100 and is thus the home zone of the primary subscriber identityused by mobile device 100, while location areas 414 and 416 comprise thevisited zone(s).

Mobile device 100 is shown connected to network 410 in a location area414 (i.e., in the visited zone). Accordingly, mobile device 100 may beconsidered to be roaming regionally within the home network 410.

Managing Identities

Referring now to FIG. 5, there is shown a flowchart diagram for anexample method of managing subscriber identities at a mobile device.

Method 500 begins at 505, with a mobile device, such as mobile device100 of FIG. 1, establishing or re-establishing a connection to awireless network, such as network 200 of FIG. 2.

In some embodiments, the mobile device may determine its currentlocation at 510. Location may be determined based on a property of thenetwork 200 to which mobile device is connected, such as the HNI or LAI.In some cases, location may be determined using wireless locationtechniques, such as GPS or Assisted GPS (A-GPS).

At 515, the mobile device may determine whether its current locationcorresponds to a home zone or a visited zone for its current subscriberidentity (e.g., a primary subscriber identity, which may also correspondto a temporary subscriber identity previously assigned to the mobiledevice).

As described herein, a home zone may be a home network associated withthe primary subscriber identity of the mobile device, or a “local”location area within the home network. Correspondingly, a visited zonemay be a visited network, or a “non-local” location area within the homenetwork.

If the current location is in the home zone (i.e., home network or locallocation area) associated with the primary subscriber identity, thenmethod 500 ends.

If, based on the primary subscriber identity, the current location is ina visited zone (i.e., visited network or non-local location area),mobile device may transmit a temporary identity request to a subscriberidentity server, such as subscriber identity server 290 of FIG. 3, at525.

In response to the request, the mobile device may receive a temporarysubscriber identity from the subscriber identity server at 530.

In some embodiments, the mobile device may not perform acts 510 and 515,and may instead receive a notification that a temporary subscriberidentity is available, at 520. In such cases, the mobile device mayoptionally transmit the temporary identity request at 525, or may simplyreceive the temporary subscriber identity at 530.

Generally, the temporary subscriber identity is selected based on thecurrent location of the mobile device. More particularly, the temporarysubscriber identity can be selected so that the current location of themobile device is within the home zone (i.e., home network or localcalling area) associated with the temporary subscriber identity.

At 535, the mobile device stores the temporary subscriber identity andthe respective subscriber information associated with the identity(e.g., IMSI, MSISDN, etc.). The temporary subscriber identity may bestored in a programmable SIM card (e.g., SIM/RUIM 126 of FIG. 1), in amemory (e.g., memory 108 of FIG. 1), or in programmable identity module160 of FIG. 1. In some cases, the programmable SIM supports concurrentstorage of a plurality of identities. In some cases, the temporarysubscriber identity may replace the primary subscriber identity in thememory or programmable SIM card or identity module. In other cases, thetemporary subscriber identity may be stored in a secondary programmableSIM/RUIM or in programmable identity module 160. If more than onesubscriber identity is stored concurrently at the mobile device, a userinterface may be provided for selecting between identities.Alternatively, mobile device may automatically select a suitablesubscriber identity based on the network or location area to which it isconnected. That is, mobile device may automatically select a subscriberidentity such that the home zone associated with the selected subscriberidentity corresponds to the current location.

Optionally, at 540, the mobile device may transmit a forwarding request,for example to the host system, HLR or other router associated with theprimary subscriber identity, to forward incoming calls and othercommunications to the temporary subscriber identity (or, in some cases,to the mobile device itself).

At 545, the mobile device may initialize itself to use the temporarysubscriber identity. Initialization may comprise rebooting the device,or simply re-connecting to the network using the temporary subscriberidentity at 505.

At a later time, method 500 may optionally continue to 605 of FIG. 6,which will be described presently.

Referring now to FIG. 6, there is shown a flowchart diagram for afurther method of managing subscriber identity of FIG. 5, in which atemporary subscriber identity can be released by a mobile device and theprimary subscriber identity restored.

Method 600 may be performed when a mobile device has a temporarysubscriber identity that was previously assigned (e.g., using method 500of FIG. 5) and which is currently stored or in use by the mobile device.Method 600 begins at 605, with a mobile device, such as mobile device100, establishing or re-establishing a connection to a wireless network,such as network 200.

In some embodiments, the mobile device may determine its location at610, which may be performed in similar fashion as at 510 of method 500.

At 615, the mobile device may determine whether its current locationcorresponds to the home zone associated with the primary subscriberidentity or a visited zone.

If the current location is in the home zone associated with thetemporary subscriber identity, then method 600 may end.

If the current location is in a different visited zone, such that thehome zone associated with the temporary subscriber identity differs fromthe zone at the current location, or if the current location is in thehome zone associated with the primary subscriber identity, then themobile device may transmit an identity release request to a subscriberidentity server, such as subscriber identity server 290 of FIG. 3, at625. The identity release request may identify the temporary subscriberidentity, for example, by IMSI.

In some embodiments, the mobile device may not perform acts 610, 615 and625, and may instead receive a notification comprising instructions torelease the temporary subscriber identity and resume using the primarysubscriber identity, at 620. In such cases, the mobile device mayoptionally transmit the identity release request at 625, or may simplyresume using the primary subscriber identity, if it is stored locally atthe mobile device.

At 630, the memory or programmable SIM or identity module at the mobiledevice can be reprogrammed to remove the temporary subscriber identity,and another subscriber identity (e.g., the primary subscriber identity)can be stored instead.

Optionally, if forwarding was configured at 540 of method 500, then aremove forwarding request can be transmitted at 640.

At 645, the mobile device may initialize itself to use the primarysubscriber identity. Initialization may comprise rebooting the device,or simply re-connecting to the network using the primary subscriberidentity.

Referring now to FIG. 7, there is shown a flowchart diagram for anexample method of managing subscriber identities at a subscriberidentity server. The subscriber identity server may manage subscriberidentities for at least one mobile device, and may manage identities fora plurality of mobile devices.

Method 700 may begin at 705 or 710, with a subscriber identityserver—such as subscriber identity server 290—determining that themobile device is connected in a visited zone other than a home zoneassociated with the primary subscriber identity of a mobile device. At705, the subscriber identity server receives a temporary identityrequest from the mobile device identifying the current location.Alternatively (or additionally), at 710, the subscriber identity serverreceives a notification that the mobile device, which is managed by thesubscriber identity server, has connected to a network in a visited zone(i.e., a visited network or non-local area based on its current, primarysubscriber identity).

At 715, the subscriber identity server selects an available temporarysubscriber identity from a plurality of available subscriber identitiesin a subscriber identity database or pool, such as database 295 of FIG.3. Selection of the temporary subscriber identity entails selecting thesubscriber information (e.g., IMSI, MSISDN, etc.) that makes up thetemporary subscriber identity (i.e., not a physical SIM card that storesthe identity).

The temporary subscriber identity may be selected such that the homezone associated with the temporary subscriber identity corresponds tothe current location of the mobile device.

If more than one suitable temporary subscriber identity is available,the subscriber identity server may select the subscriber identity basedon predefined selection criteria. Predefined selection criteria mayinclude the least recent “last used” date, lowest billing costsassociated with the temporary subscriber identity, previous use (e.g.,has the subscriber used the temporary subscriber identity before), orcombinations thereof. If no suitable temporary subscriber identity isavailable, the subscriber identity server may return an error message,or discontinue method 700.

At 720, the selected temporary subscriber identity can be transmitted tothe mobile device and, at 725, the database may be updated to indicatethat the selected temporary subscriber identity is in use. The databasemay also be updated to record the subscriber using the temporarysubscriber identity, the subscriber's primary subscriber identity, thecurrent date and time, and combinations thereof.

Optionally, at 730, the subscriber identity server may transmit aforwarding request, for example to the host system, HLR or other routerassociated with the primary subscriber identity, to forward incomingcalls and other communications to the temporary subscriber identity (or,in some cases, to the mobile device itself).

The mobile device may be programmed to use the temporary subscriberidentity, as described with reference to method 500 FIG. 5.

Likewise, the mobile device may perform method 600 of FIG. 6 uponentering a different zone.

Accordingly, at 740 or 745, the subscriber identity server receives anotification that the mobile device has changed zones. At 740, thesubscriber identity server may receive an identity release request fromthe mobile device identifying the temporary subscriber identity to bereleased. Alternatively (or additionally), at 745 the subscriberidentity server may receive a notification that the mobile device haschanged zones, for example by connecting to a new visited network,returning to the home network of the primary subscriber identity, orentering a new location area within the network.

At 750, the subscriber identity server may transmit a notification tothe mobile device comprising instructions to release the temporarysubscriber entity and resume using the primary subscriber entity.Resuming use of the primary subscriber identity may comprisereprogramming a memory, SIM or programmable identity module with theprimary subscriber identity, which in some cases may be retrieved overthe network from the subscriber identity server, for example.

At 755, the database may be updated to indicate that the temporarysubscriber identity is once again available for use by other mobiledevices, if desired. The database may also be updated to indicate thecurrent date and time that the temporary subscriber identity wasreleased and made available. In some cases, the database may be updatedto indicate a “waiting period” before the temporary subscriber identityis made available. This may avoid or reduce the incidence ofcommunications being directed to a subsequent subscriber by anindividual or device that is unaware that the temporary subscriberidentity is no longer in use by an earlier user.

Optionally, if forwarding was configured at 730 of method 700, then aremove forwarding request can be transmitted at 760.

It should be understood that various modifications can be made to theembodiments described and illustrated herein, without departing from theembodiments, the general scope of which is defined in the appendedclaims.

The invention claimed is:
 1. A method for managing subscriber identitieson a mobile device during regional roaming, the mobile device having aprimary subscriber identity associated therewith, the primary subscriberidentity being associated with a first location area in a home network,the method comprising: wirelessly receiving a temporary subscriberidentity from a subscriber identity server while the mobile device islocated in a second location area in the home network, the secondlocation area having a different Location Area Code than the firstlocation area; storing the temporary subscriber identity in a memory ofthe mobile device; and initializing the mobile device to use thetemporary subscriber identity.
 2. The method of claim 1, furthercomprising: prior to receiving the temporary subscriber identity,detecting that the mobile device is located in the second location area;and in response to the detecting, transmitting a temporary identityrequest to the subscriber identity server, the temporary identityrequest comprising an indication of the second location area.
 3. Themethod of claim 1, further comprising, prior to initializing the mobiledevice to use the temporary subscriber identity, transmitting a requestto a host system to forward communications addressed to the primarysubscriber identity to the temporary subscriber identity.
 4. The methodof claim 1, further comprising: detecting that the mobile device haschanged its location from the second location area to the first locationarea; transmitting a release request to the subscriber identity serverto release the temporary subscriber identity; and re-initializing themobile device to use the primary subscriber identity.
 5. The method ofclaim 1, wherein the memory is a programmable subscriber identity moduleprovided on the mobile device.
 6. A method at a subscriber identityserver for managing identity of a mobile device during regional roaming,wherein the mobile device has a primary subscriber identity associatedtherewith, the primary subscriber identity being associated with a firstlocation area in a home network, the method comprising: determining thatthe mobile device is located in a second location area in the homenetwork, the second location area having a different Location Area Codethan the first location area; selecting a temporary subscriber identityfrom a plurality of available identities, wherein the selected temporarysubscriber identity is associated with the second location area; andtransmitting the selected temporary subscriber identity to the mobiledevice.
 7. The method of claim 6, wherein the determining comprisesreceiving a temporary identity request from the mobile device, thetemporary identity request comprising an indication of the secondlocation area.
 8. The method of claim 6, further comprising transmittinga request to a host system to forward communications addressed to theprimary subscriber identity to the temporary subscriber identity.
 9. Themethod of claim 6, further comprising updating a database to indicatethat the temporary subscriber identity has been assigned to the mobiledevice.
 10. The method of claim 9, further comprising: receiving anotification that the mobile device has changed location; and updatingthe database to indicate that the temporary subscriber identity is nolonger assigned to the mobile device.
 11. A mobile device having aprimary subscriber identity associated therewith, the primary subscriberidentity being associated with a first location area in a home network,the mobile device comprising: a memory; a communication subsystemconfigured to wirelessly receive a temporary subscriber identity from asubscriber identity server while the mobile device is located in asecond location area in the home network during regional roaming, thesecond location area having a different Location Area Code than thefirst location area; a processor configured to: store the temporarysubscriber identity in the memory of the mobile device; and initializethe mobile device to use the temporary subscriber identity.
 12. Themobile device of claim 11, wherein the mobile device is configured to:prior to receiving the temporary subscriber identity, detect that themobile device is located in the second location area; and in response tothe detecting, transmit a temporary identity request to the subscriberidentity server, the temporary identity request comprising an indicationof the second location area.
 13. The mobile device of claim 11, whereinthe mobile device is configured to: prior to initializing the mobiledevice to use the temporary subscriber identity, transmit a request to ahost system to forward communications addressed to the primarysubscriber identity to the temporary subscriber identity.
 14. The mobiledevice of claim 11, wherein the mobile device is configured to: detectthat the mobile device has changed its location from the second locationarea to the first location area; transmit a release request to thesubscriber identity server to release the temporary subscriber identity;and re-initialize the mobile device to use the primary subscriberidentity.
 15. The mobile device of claim 11, wherein the memory is aprogrammable subscriber identity module provided on the mobile device.16. An apparatus for managing identity of a mobile device duringregional roaming, wherein the mobile device has a primary subscriberidentity associated therewith, the primary subscriber identity beingassociated with a first location area in a home network, the apparatuscomprising: a database configured to store a plurality of availableidentities; a processor configured to: determine that the mobile deviceis located in a second location area in the home network, the secondlocation area having a different Location Area Code than the firstlocation area; select a temporary subscriber identity from the pluralityof available identities, wherein the selected temporary subscriberidentity is associated with the second location area; and transmit theselected temporary subscriber identity to the mobile device.
 17. Theapparatus of claim 16, wherein the determining comprises receiving atemporary identity request from the mobile device, the temporaryidentity request comprising an indication of the second location area.18. The apparatus of claim 16, wherein the apparatus is configured totransmit a request to a host system to forward communications addressedto the primary subscriber identity to the temporary subscriber identity.19. The apparatus of claim 16, wherein the apparatus is configured toupdate a database to indicate that the temporary subscriber identity hasbeen assigned to the mobile device.
 20. The apparatus of claim 19,wherein the apparatus is configured to: receive a notification that themobile device has changed location; and update the database to indicatethat the temporary subscriber identity is no longer assigned to themobile device.